Milk shakes are comprised of aqueous emulsions which are foamed by being whipped with air. When a conventional milk shake product is stored in a container at refrigerator temperatures, the foam rapidly collapses, and the result is a substantial loss in the volume of the product during storage. Thus, conventional milk shakes such as those sold by fast-food restaurants must be consumed shortly after they are prepared and cannot be stored at refrigerator temperatures for longer than about one hour. At freezer temperatures such shake products freeze solid and require a lengthy thawing period before they can be consumed with either a spoon or a straw.
Frozen foods such as frozen vegetables, etc. are stored in supermarket freezers at about 0.degree. F. However, ice creams are conventionally stored in supermarket freezers at temperatures of about -20.degree. F., since at freezer temperatures of about 0.degree. F., a substantial loss of product volume is typically observed after less than about a one-month storage period. Moreover, when stored at about 0.degree. F., conventional ice cream products tend to become crystalline and grainy. From an energy consumption standpoint, the requirement of -20.degree. F. storage temperature for ice cream products is economically disadvantageous.
It is an object of this invention to provide whipped ice cream and milk shake products which maintain a stable volume when stored for prolonged periods at refrigerator temperatures, as well as at the economically advantageous freezer storage temperature of about 0.degree. F. It is also an object of this invention to provide whipped products which remain in a substantially noncrystalline and spoonable state at freezer temperatures of about 0.degree. F. and, therefore, do not require a prolonged thawing period prior to consumption.
Other objects and advantages of this invention will be apparent from the description of this invention which follows.